<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style>	
			*{
				margin: 0;
				padding: 0;
			}	
			body{
				background-color: #5889A7;
			}
			/* 容器 <div> - 需要定位下拉内容 */			
			.box {
				position: relative;
			}
			
			/* 下拉按钮样式 */			
			.box .down {
				width: 200px;
				height: 50px;
				position: absolute;
				top: 20px;
				left: 904px;
				border: none;
				background-color: #4CAF50;
				color: white;
				font-size: 16px;
				cursor: pointer;
			}
			
			/* 下拉内容 (默认隐藏) */			
			.box-content {				
				position: absolute;
				left: 904px;
				top: 70px;
				background-color: #EDEEF0;
				display: none;
			}
			
			/* 下拉菜单的链接 */			
			.box-content a {
				width: 200px;
				height: 100px;
				color: black;
				text-align: center;
				line-height: 100px;
				text-decoration: none;
				display: block;
			}
			
			/* 鼠标移上去后修改下拉菜单链接颜色 */			
			.box-content a:hover {
				background-color: #E8D8CB;
			}
			
			/* 在鼠标移上去后显示下拉菜单 */			
			.box:hover .box-content {
				display: block;
			}
			
			/* 当下拉内容显示后修改下拉按钮的背景颜色 */			
			.box:hover .down {
				background-color: #3e8e41;
			}
		</style>
	</head>

	<body>
		<div class="box">
			<button class="down">下拉菜单</button>
			<div class="box-content">
				<a href="#">菜单内容1</a>
				<a href="#">菜单内容 2</a>
				<a href="#">菜单内容 3</a>
			</div>
		</div>
	</body>

</html>